Because of this problem, I always make sure that paragraphs always are complete before a picture. At least the reader doesn't have to hold a thought as they skip over a picture.
Image maps don't work in epubs, so any link would have to be in the caption. If you have larger tablets as your target, then this sort of linking is worthwhile. For smaller readers, the detail and grayscale just aren't there to make it worthwhile, in my opinion.